Various micromechanical devices, such as micromechanical gyroscopes, require vacuum sealing in order to ensure long-term, accurate operation. Conventional vacuum sealing is achieved by mounting the device in a vacuum sealed housing or enclosure. Input and output electrical connections to and from the enclosed device are provided by embedding conductors through portions of the enclosure to permit conductive traces or wires to be connected to the device.
However, this type of vacuum sealed enclosure tends to be relatively costly. Moreover, tolerances associated with mounting the device in the enclosure may affect the accuracy of a device which is sensitive to spatial orientation. For example, some inertial systems utilize three inertial rate sensors arranged orthogonally with respect to one another. When each such sensor is mounted in a respective vacuum sealed enclosure, tolerances associated with mounting each sensor in the respective enclosure, as well as tolerances associated with mounting the enclosed packages in orthogonal relationship with respect to each other, may adversely affect the accuracy of the system. As is known in the integrated circuit field, various package formats are available for mounting integrated circuits, or chips to wiring boards, printed circuit boards, and other support substrates. For example, flip chips include conductive bumps, or balls for interconnection to complementary pads on a wiring board. The flip chip conductive bumps may be soldered to the circuit board pads or pressed against the circuit board pads so as to provide and maintain reliable electrical interconnection between the conductive bumps of the chip and the complementary conductive pads on the circuit board.
Tape automated bonding (TAB) is another known technique for interconnecting chips to wiring boards. In accordance with this technique, conductive finger-like members cantilevered from conductive pads on the semiconductor chip are bonded to respective pads on the circuit board. Another illustrative technique employed to electrically interconnect chip pads to circuit board pads is wire bonding, in which gold or aluminum wires are bonded to connect the chip pads to the circuit board pads.